Sack closing instrument



FIG. 1 is a top, front and left side perspective view of a sack closing instrument showing my new design;

FIG. 2 is a top, rear and left side perspective view;

FIG. 3 is a top plan view;

FIG. 4 is a front elevational view;

FIG. 5 is a bottom plan view;

FIG. 6 is a left side elevational view;

FIG. 7 is a right side elevational view; and,

FIG. 8 is a rear elevational view thereof. 

The ornamental design for a sack closing instrument, as shown. 